PRODUCT CATALOGUE 2024 | alre.de

TECHNICAL ANNEX

TECHNICAL TERMS

TECHNICAL TERMS

DEFINITION / EXPLANATION

Continuous control:

The controller provides an analogue output signal. The value of the output signal changes continuously, i.e., without any steps or jumps, in response to the output signal. The TR is also implemented via a resistor, as is the case with thermal recirculation. This resistor is activated manually or by a timer. As a result, the bimetal is made to feel a simulated temperature that is about 4 K higher than the actual temperature in the room. Consequently, in a room with a controller setting of, for example, 20 °C, the temperature in the room can drop to a value 4 K lower, to max. 16 °C. If the temperature drops further, the heating system switches on again, and at > 16 °C, it gets switched off. The magnitude of the temperature reduction to be actually achieved depends on the insulation of the building and the reduction period (one night, weekend, holiday). By means of an additional integrated heating resistor, the controller is made to switch off at the right time during the heating process. As a result, exceeding the desired room temperature is minimised, and there is a smaller switching difference. Rooms can be cooled or heated with heat pumps. Modern systems allow efficient heating and cooling oper - ation since they allow reversible process reversing. A reversing valve (4-way control valve) facilitates a reversing cycle by turning the condenser (liquefier) into an evaporator which causes the cooling unit to heat up or defrost. Valve and pump protection serves to prevent the valve seat and / or pumps from corroding during long downtimes. It is recommended to activate valve protection for hot water heating systems. If valve and pump protection is activated, the valve or a heating pump is operated once on Mondays between 1100hrs and 1200hrs for 5 minutes. Valve and pump protection only becomes active if no heating has taken place within the last week. This avoids unnecessary additional heating at times of year when heating is in use and does not affect the control system. A liquefier or condenser is a heat exchanger in a cooling unit that liquefies a gaseous medium through the dissipation of heat. Usually, further cooling of the cooling agent takes place in the liquefier. According to the definition of terms in the European Standard EN 378 Part 1, the condenser in cooling units is called the liquefier in order to easily distinguish it from an electrical condenser. The vaporiser implements the opposite process, evaporating the liquid medium by heating it up.

Temperature reduction (TR):

Thermal recirculation (RF):

Heat pump:

Reversing valve:

Valve protection function

Evaporator / liquefier:

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Catalogue 2024

Prices valid from 01.01.2024 - 31.12.2024, prices may be subject to change | V1

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